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Meeting held Thursday, February 12, 2015, Digipen Media Lab, Redmond, WA

AES PNW Section Meeting Report
More Topics in Loudness - ?Microdynamics?
with James (JJ) Johnston
Independent Audio and Electroacoustics Consultant
AES Fellow and PNW AES Committee Member
image linked to dtl_feb2015.jpg
PNE AES Section Chair Dave Tosti-Lane begins the meeting with announcements. 		image linked to jj_feb2015.jpg
JJ Johnston expands on a point relating to the variation of loudness in recordings 		image linked to crowd_feb2015.jpg
The audience reacts to the festivities during door prize awarding.

lplt_t3.m Octave program 

Video recordings of the meeting:

Photos by Bob Gudgel, Video recording by Dan Mortensen


What Is Microdynamics?
This is the question James D. (jj) Johnston presented to the group at the PNW Section February meeting, held at the Digipen Institute of Technology in Redmond, WA. He said it was neither Dynamic Range nor RMS; and loosely defined as "variation in loudness" based on an insufficient number of experiments. After a short review of terms (such as "loudness"), he presented some challenges of using dynamic range as a measure of microdynamics with some examples of number sequences that can "break" a dynamic range calculation. This was followed by the introduction of a matlab/octave script (lplt_t.m) that he wrote ( right-click this link to download)  that analyzes sound files based on a loudness model.

The rest of the talk was spent looking at the results of different program material processed with the script, demonstrating how the various plots corresponded to audible effects in the material.

We took a break, after which, as is our custom, door prizes were awarded:

  • Fluke Volt 1 - won by Anastasia Groves, Dave Ellis
  • AES Hand Sanitizer - won by Ed Gruse
  • RGB Short Connect Cable set - won by Greg Mauser
  • Amprobe Meter - won by Rob Riggs
  • Vintage King T Shirt - won by Deepak Chennakkadan

After the break and door prizes, Bob Smith gave a short presentation on how to install Octave (an open-source version of Matlab "matrix laboratory") with minimal pain, pointing out some of the pitfalls of the installation process.

Those interested in digging further into the topic of loudness might find the meeting recap from JJ's January 2014 session "Dynamic Range, How Low Can You Go"  worth a look.

Reported by Chris Deckard, PNW Section Committee Member


Last modified 05/26/2016 2:27:47 (rc).